Low energy muons as probes of thin films and surfaces

Polarized muons with kinetic energies of a few eV (epithermal μ+) can be generated by slowing down energetic muons in appropriate moderators consisting of a thin layer of a van der Waals gas frozen on a substrate. The availability of polarized muons with kinetic energies in the eV to several keV range opens the possibility to extend the μSR technique to the study of thin films and surfaces (low energy μSR, LE-μSR). We summarize the characteristics of the very slow polarized muons and of a low energy beam based on the moderation technique. We discuss the implantation of muons in thin film samples and the potential and limitations of LE-μSR. As an example first results obtained by implanting slow μ+ in a sample consisting of a Ni film deposited on Ag are presente

The Black Male\u27s Perception of Academic Success in the Black Belt Region

The purpose of this applied dissertation was to explore the perceptions of academic success of Black males in the Black Belt in an effort for educators and community members to better understand and meet the needs of young Black men. In this study, the researcher conducted one 60-minute interview followed by one confirming interview with nine former students (Appendix D) who graduated from the local area high school. Interview questions (Appendix B) were developed by the researcher based on the research questions in the study. These use of these questions assisted in understanding the perceptions of academic success of these young Black men. From an analysis of the data gathered from the young men’s interviews, three prevalent themes emerged: 1) the meaning of academic success, 2) the role of the stakeholders, and 3) a boy’s only club. This study will allow educators and community members to examine the highlighted issues and to consider appropriate actions to meet the needs of young Black men

Prêcher sur les reliques de la Passion à l'époque de saint Louis

Etude des principaux thèmes abordés par les prédicateurs du XIIIe siècle lors des fêtes des reliques de la Sainte-Chapell

Proximal magnetometry of monolayers of magnetic moments

We present a method to measure the magnetic properties of monolayers and ultra-thin films of magnetic material. The method is based on low energy muon spin rotation and $\beta$-detected nuclear magnetic resonance measurements. A spin probe is used as a "proximal" magnetometer by implanting it in the substrate, just below the magnetic material. We calculate the expected magnetic field distribution sensed by the probe and discuss its temperature and implantation depth dependencies. This method is highly suitable for measuring the magnetic properties of monolayers of single molecule magnets, but can also be extended to ultra-thin magnetic films.Comment: To be published in the proceedings of 12th International Conference on Muon Spin Rotation, Relaxation and Resonanc

Ordering in weakly coupled random singlet spin chains

The influence of bond randomness on long range magnetic ordering in the weakly coupled S = 1/2 antiferromagnetic spin chain materials Cu(py)2(Cl1-xBrx)2 is studied by muon spin rotation and bulk measurements. Disorder is found to have a strong effect on the ordering temperature TN, and an even stronger one on the saturation magnetization m0, but considerably more so in the effectively lower-dimensional Br-rich materials. The observed behavior is attributed to Random Singlet ground states of individual spin chains, but remains in contradiction with chain mean field theory predictions. In this context, we discuss the possibility of a universal distribution of ordered moments in the weakly coupled Random Singlet chains model